Abstract
Class A beta-lactamases of the TEM family contain a single disulphide bond which connects cysteine residues 77 and 123. To clarify the possible role of the disulphide bond in the stability and folding kinetics of the TEM-1 beta-lactamase, this bond was removed by introducing a Cys-77-->Ser mutation, and the enzymically active mutant protein was studied by reversible guanidine hydrochloride-induced denaturation. The unfolding and refolding rates were monitored using tryptophan fluorescence. At low guanidine hydrochloride concentrations, the refolding of the wild-type and mutant enzymes followed biphasic time courses. The characteristics of the two phases were not significantly affected by the mutation. Double-jump experiments, in which the protein was unfolded in a high concentration of guanidine hydrochloride for a short time period and then refolded by diluting out the denaturant, indicated that, for both the wild-type and mutant enzymes, the two refolding phases could be ascribed to proline isomerization reactions. Equilibrium unfolding experiments monitored by fluorescence spectroscopy and far-UV CD indicated a three-state mechanism (N<-->H<--U). Both the folded mutant protein (N) and, to a lesser extent the thermodynamically stable intermediate, H. were destabilized relative to the fully unfolded state, U. Removal of the disulphide bond resulted in a decrease of 14.2 kJ/mol (3.4 kcal/mol) in the global free energy of stabilization. Similarly, the mutation also induced a drastic increase in the rate of thermal inactivation.
Full Text
The Full Text of this article is available as a PDF (358.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anfinsen C. B., Scheraga H. A. Experimental and theoretical aspects of protein folding. Adv Protein Chem. 1975;29:205–300. doi: 10.1016/s0065-3233(08)60413-1. [DOI] [PubMed] [Google Scholar]
- Betz S. F. Disulfide bonds and the stability of globular proteins. Protein Sci. 1993 Oct;2(10):1551–1558. doi: 10.1002/pro.5560021002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clarke J., Fersht A. R. Engineered disulfide bonds as probes of the folding pathway of barnase: increasing the stability of proteins against the rate of denaturation. Biochemistry. 1993 Apr 27;32(16):4322–4329. doi: 10.1021/bi00067a022. [DOI] [PubMed] [Google Scholar]
- Denton M. E., Rothwarf D. M., Scheraga H. A. Kinetics of folding of guanidine-denatured hen egg white lysozyme and carboxymethyl(Cys6,Cys127)-lysozyme: a stopped-flow absorbance and fluorescence study. Biochemistry. 1994 Sep 20;33(37):11225–11236. doi: 10.1021/bi00203a019. [DOI] [PubMed] [Google Scholar]
- Doig A. J., Williams D. H. Is the hydrophobic effect stabilizing or destabilizing in proteins? The contribution of disulphide bonds to protein stability. J Mol Biol. 1991 Jan 20;217(2):389–398. doi: 10.1016/0022-2836(91)90551-g. [DOI] [PubMed] [Google Scholar]
- Dubus A., Wilkin J. M., Raquet X., Normark S., Frère J. M. Catalytic mechanism of active-site serine beta-lactamases: role of the conserved hydroxy group of the Lys-Thr(Ser)-Gly triad. Biochem J. 1994 Jul 15;301(Pt 2):485–494. doi: 10.1042/bj3010485. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jelsch C., Lenfant F., Masson J. M., Samama J. P. Crystallization and preliminary crystallographic data on Escherichia coli TEM1 beta-lactamase. J Mol Biol. 1992 Jan 5;223(1):377–380. doi: 10.1016/0022-2836(92)90739-7. [DOI] [PubMed] [Google Scholar]
- Laminet A. A., Plückthun A. The precursor of beta-lactamase: purification, properties and folding kinetics. EMBO J. 1989 May;8(5):1469–1477. doi: 10.1002/j.1460-2075.1989.tb03530.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matagne A., Misselyn-Bauduin A. M., Joris B., Erpicum T., Granier B., Frère J. M. The diversity of the catalytic properties of class A beta-lactamases. Biochem J. 1990 Jan 1;265(1):131–146. doi: 10.1042/bj2650131. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matouschek A., Kellis J. T., Jr, Serrano L., Bycroft M., Fersht A. R. Transient folding intermediates characterized by protein engineering. Nature. 1990 Aug 2;346(6283):440–445. doi: 10.1038/346440a0. [DOI] [PubMed] [Google Scholar]
- Matsumura M., Becktel W. J., Levitt M., Matthews B. W. Stabilization of phage T4 lysozyme by engineered disulfide bonds. Proc Natl Acad Sci U S A. 1989 Sep;86(17):6562–6566. doi: 10.1073/pnas.86.17.6562. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matsumura M., Matthews B. W. Stabilization of functional proteins by introduction of multiple disulfide bonds. Methods Enzymol. 1991;202:336–356. doi: 10.1016/0076-6879(91)02018-5. [DOI] [PubMed] [Google Scholar]
- Mitchinson C., Pain R. H. Effects of sulphate and urea on the stability and reversible unfolding of beta-lactamase from Staphylococcus aureus. Implications for the folding pathway of beta-lactamase. J Mol Biol. 1985 Jul 20;184(2):331–342. doi: 10.1016/0022-2836(85)90384-5. [DOI] [PubMed] [Google Scholar]
- Mücke M., Schmid F. X. Folding mechanism of ribonuclease T1 in the absence of the disulfide bonds. Biochemistry. 1994 Dec 6;33(48):14608–14619. doi: 10.1021/bi00252a029. [DOI] [PubMed] [Google Scholar]
- Pace C. N., Grimsley G. R., Thomson J. A., Barnett B. J. Conformational stability and activity of ribonuclease T1 with zero, one, and two intact disulfide bonds. J Biol Chem. 1988 Aug 25;263(24):11820–11825. [PubMed] [Google Scholar]
- Raquet X., Lamotte-Brasseur J., Fonzé E., Goussard S., Courvalin P., Frère J. M. TEM beta-lactamase mutants hydrolysing third-generation cephalosporins. A kinetic and molecular modelling analysis. J Mol Biol. 1994 Dec 16;244(5):625–639. doi: 10.1006/jmbi.1994.1756. [DOI] [PubMed] [Google Scholar]
- Schellman J. A. The thermodynamic stability of proteins. Annu Rev Biophys Biophys Chem. 1987;16:115–137. doi: 10.1146/annurev.bb.16.060187.000555. [DOI] [PubMed] [Google Scholar]
- Schultz S. C., Dalbadie-McFarland G., Neitzel J. J., Richards J. H. Stability of wild-type and mutant RTEM-1 beta-lactamases: effect of the disulfide bond. Proteins. 1987;2(4):290–297. doi: 10.1002/prot.340020405. [DOI] [PubMed] [Google Scholar]
- Strynadka N. C., Adachi H., Jensen S. E., Johns K., Sielecki A., Betzel C., Sutoh K., James M. N. Molecular structure of the acyl-enzyme intermediate in beta-lactam hydrolysis at 1.7 A resolution. Nature. 1992 Oct 22;359(6397):700–705. doi: 10.1038/359700a0. [DOI] [PubMed] [Google Scholar]
- Taniyama Y., Ogasahara K., Yutani K., Kikuchi M. Folding mechanism of mutant human lysozyme C77/95A with increased secretion efficiency in yeast. J Biol Chem. 1992 Mar 5;267(7):4619–4624. [PubMed] [Google Scholar]
- Vanhove M., Houba S., b1motte-Brasseur J., Frère J. M. Probing the determinants of protein stability: comparison of class A beta-lactamases. Biochem J. 1995 Jun 15;308(Pt 3):859–864. doi: 10.1042/bj3080859. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vanhove M., Raquet X., Frère J. M. Investigation of the folding pathway of the TEM-1 beta-lactamase. Proteins. 1995 Jun;22(2):110–118. doi: 10.1002/prot.340220204. [DOI] [PubMed] [Google Scholar]
- Vanhove M., Raquet X., Palzkill T., Pain R. H., Frère J. M. The rate-limiting step in the folding of the cis-Pro167Thr mutant of TEM-1 beta-lactamase is the trans to cis isomerization of a non-proline peptide bond. Proteins. 1996 May;25(1):104–111. doi: 10.1002/(SICI)1097-0134(199605)25:1<104::AID-PROT8>3.0.CO;2-J. [DOI] [PubMed] [Google Scholar]
- Walker K. W., Gilbert H. F. Oxidation of kinetically trapped thiols by protein disulfide isomerase. Biochemistry. 1995 Oct 17;34(41):13642–13650. doi: 10.1021/bi00041a045. [DOI] [PubMed] [Google Scholar]
- Zahn R., Axmann S. E., Rücknagel K. P., Jaeger E., Laminet A. A., Plückthun A. Thermodynamic partitioning model for hydrophobic binding of polypeptides by GroEL. I. GroEL recognizes the signal sequences of beta-lactamase precursor. J Mol Biol. 1994 Sep 16;242(2):150–164. doi: 10.1006/jmbi.1994.1566. [DOI] [PubMed] [Google Scholar]